Method of removing free oxygen from water



Patented Mar. 31, 1925.

UNITED vSTATES FRANK N. SPELLER, 0F PITTSBURGH, PENNSYLVANIA.

METHOD OF REMOVING FREE OXYGEN FROM WATER.

No. Drawing.

To all whom it mag/concern:

Be it known that I, FRANK N. SPELLER, a citizen of the United States, and resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Methods of Removing Free Oxygen from lVater, of which the following is a specification.

My invention relates to the removal from water of the free oxygen contained therein, and the production of a supply of water which contains no free oxygen and is substantially non-corrosive.

One object of my invention is the provision of a novel method of treating water whereby any free oxygen present therein is removed in a rapid, effective and economical manner, whereby a substantially continuous method is secured which functions automatically and through extended time intervals, and wherein the use of a filter is avoided or at least unnecessary.

Water used for domestic purposes is usually slightly acid to phenolphthalein and very rarely, if ever, is alkaline enough to enable my improved method to be carried out, so that the water to be treated will be made alkaline beforehand to the,slight extent necessary in practicing my invention.

Where alkalinity is referred to in the specification and claims, it should be understood that this refers to alkalinity measured by phenolphthalein as an indicator.

A preferred way of rendering the water alkaline is by causing it to flow over or through a bed of burned magnesite, or alkaline anhydrous sodium silicate, or similar material, preparatory to the removal of the free oxygen.

In preparation for the installation or use of my improved method, the average consumption of hot water used ina definite time intervals (for example say one hour) isdetermined in a particular system, and also whether the water is alkaline or not and if so, the degree of alkalinity also will be ascertained. It is found that in some one hour of each day a maximum amount of water will be required, so that the hour of maximum consumption will be best for such determination.

It is well known that the alkalinity of a given water supply does notcrapidly or materially change with long periods of time, so that the alkalinity can be assumed to be Application filed December 23, 1921. Serial No. 524,557.

' nearly constant, and that if not so the water will not suddenly become alkaline.

In practicing my improved method the alkaline water is heated to about 160 degrees Fahrenheit, and is then caused to flow slow- 1y over the surfaces of a mass or body of a metal having a strong affinity for oxygen. It is found that the best results are obtained when the temperature of the water is over 140 degrees Fahrenheit, and its alkalinity about 20 parts per million, with the rate of flow of the Water through the bed of metal up to five or six inches per minute. In some cases the water may be heated before making it alkaline, and it is to be understood that such sequence in the operations is within the scope of my invention.-

Ihe exact rate of flow of the water will depend upon its alkalinity and temperature and the rate of flow will be controlled with changes in the alkalinity and temperature of the water being treated in carrying out my improved method. For example, when the alkalinity is reduced the rate of flow must also be reduced or the temperature increased.

I have found that a preferred way of bringing the water into contact with the body of metal is to pass the heated water downwardly through a uniform bed or layer of expanded ferrous metal sheets, (commonly known as expanded metal or metal lath,) of a height or thickness of approximately 30 inches. The flow of the water in its passage through the body of expanded metal sheets is controlled so as to cause a velocity of from one-half inch to ordinarily not exceeding five inches per minute. Of course slight variations, above and below these limits may be made, within the scope of the invention. The maximum rate of flow which will produce clear water may be increased to a slight but certain extent with changes in the temperature and degree of alkalinity of the water, but tests show about 160 degrees Fahrenheit and 20 to 30 parts per million alkalinity afiords the best results in producing clear, oxygen free water.

When iron rusts in water a certain amount of colloidal ferric hydrate is formed, which is objectional because it discolors the water and can not be readily filtered. By making the water somewhat more alkaline this hydrate will adhere very tenaciously to the metal and is not readily dislodged therefrom and washed away, unless the rate of flow of the water becomes excessive, and in this way the necessity of filtering the water is avoided and overcome.

In the passage of the water through the body of expanded metal the hydroxides will adhere to the surface of the sheets with which it contacts and form a loose coating thereon, the water passed through the body of expanded metal being found to be clear and free of rust. It also is found that with the other factors the same, that by passing the water downwardly instead of upwardly the rust formed by the oxygen adheres better to and is more effectively retained on the surfaces of the metal sheets.

While expanded metal sheets or lath are specified as preferable in forming the ferrous body through which the water is passed, it will be understood that other metals, such as zinc, may be employed without departing from the method forming my in vention. The expanded metal sheets, be cause of their form, permit a body of the sheets to be constructed which allows the water to percolate through the pack of sheets in an ideal manner and such arrangement of sheets will not pack too tightly together and obstruct the flow of the water by contact with rust formed on the surfaces of the sheets.

The advantages of my improved method will be readily appreciated by those skilled in the art. By bringing the water, while it is slightly alkaline, into contact with the surface of the metal body and by regulation of the degree of alkalinity and temperature to which the water is heated with re gard to the rate of flow of the water through the oxygen removing body, the free oxygen is entirely removed from the water and a body of heated water is obtained which is non-corrosive, is clear and is free of rust. The use of my improved method automatically supplies either a constant or intermittent supply, as desired, of oxygen free water during extended time intervals with little or no attention.

Many modifications i the apparatus used in practicing my invention may be made without departure from m invention as defined in the appended claims.

I claim 1. The method of deoxidizing water which consists in heating slightly alkaline water and then passing the heated water through a bed of metal at a low velocity.

2. The method of deoxidizing water which consists in heating slightly alkaline water and then passing the heated water through a bed of metal at a low velocity, and regulating the speed at which the water flows through the metallic material with changes in the alkalinity of the water.

3. The method of deoxidizing water which consists in heating slightly alkaline water and then passing the heated water through a bed of metal at a low velocity, and regulating the speed at which the water flows through the metal with changes in the temperature of the heated water.

4:. The method of deoxidizing water which consists in heating slightly alkaline water and then passing the heated water slowly through a bed of metal, and rcgulating the velocity at which the water flows through the metal with changes in the alkalinity and temperature of the water.

5. The method of deoxidizing water which consists in making the water slightly alkaline, then heating the slightly alkaline water to a temperature of approximately 160 degrees Fahrenheit and then bringing the heated water into contact with a body of metallic material and regulating the flow of the water while in contact with the metallic material to not exceeding six inches per minute.

6. The method of deoxidizing water which consists in heating slightly alkaline water to a temperature of at least 140 degrees Fahrenheit andv then bringing the heated water into contact with a body of metallic material at a low velocity and regu lating the velocity of the flowing water while in contact with the ferrous material with changes in the temperature of the water.

7. The method of deoxidizing water which consists in making the water slightly alkaline, then heating the slightly alkaline water to a temperature of approximately 160 degrees Fahrenheit, and then bringing the heated water into contact with a body of metallic material at a low velocity, and regulating the Velocity of the flowing water while in contact with the metallic material with changes in the alkalinity of the water.

8. The method of deoxidizing. water which consists in making the water slightly alkaline, then heating the slightly alkaline Water to a temperature of approximately 160 degrees Fahrenheit, and then bringing the heated water into contact with a body of metallic material at a low velocity, and regulating the velocity of the flowing water while in contact with the metallic material wit-h changes in the alkalinity and temperature of the water.

9. The method of removing dissolved oxygen from Water which consists in passing heated, slightly alkaline water over a large surface of metal, maintaining the flow at a low velocity and regulating the maximum rate of flow with changes in the temperature and alkalinity of the water and thereby causing the insoluble compounds formed in treating the water to adhere to said metal surfaces.

10. The method of removing dissolved oxygen from Water, which consists in making the water slightly alkaline, then heating the water to approximately 160 degrees Fahrenheit, and then bringing the heated water into contact with a metal surface and maintaining the flow of the water at a low velocity when in contact with the body of metal and thereby causing the insoluble compounds formed to adhere to the metal.

11. The method of removing dissolved oxygen from water. which consists in making the water slightly alkaline, then heating the water to between 140 and 160 degrees Fahrenheit, and then bringing the heated water into contact with a metal surface and maintaining the flow. of the water at a low velocity when in contact with the body of metal and thereby causing the insoluble compounds formed to adhere to the metal.

12. The method of deoxidizing water, which consists in passing heated, and slight- 1y alkaline water through a bed of metal at a low velocity.

13. The method of .deoxidizing water, which consists in assing slightly alkaline water through a d of metal at a low velocity.

14. The method of deoxidizing water, which consists in makin the water sli htly alkaline, then heating tie slightly alkaline water to a temperature of approximately 160 degrees Fahrenheit, and then flowing the heated water downwardly through a uniform bed of expanded ferrous metal sheets, and regulating the velocity of the flowing water while passing through said bed of expanded ferrous metal sheets in proportion to the changes in temperature and alkalinity of the water, the maximum velocity being limited to approximately SIX inches per minute.

15. The method of deoxidizing water which consists in heating slightly alkaline water and then passing the heated water through a bed of metal having a strong aflinity for oxygen.

16. The method of deoxidizing water which consists in making the water slightly alkaline, heating the slightly alkaline water and then passing the heated water throu h a bed of metal having a strong afiinity or oxygen.

17. In a method of deoxidizing water, which includes passing the water through a bed of metal having a strong aflinity for oxygen, the step consisting in bringing the water to a state of alkalinity approx1mating 20 p. p. m. prior to passing the water through the bed of metal.

18. In a method of deoxidizing water which includes heating the water to approximately 160 degrees Fahrenheit and passing the heated water through a bed of metal having a strong afiinity for oxygen, the step consisting in bringing the water to a state of alkalinity approximating 20 p. p. In. prior to passing the water through the bed of metal.

In testimony whereof I have hereunto signed my name.

FRANK N. SPELLER. 

